4-Trifluoromethanesulfonamidyl prolinol tert-butyldiphenylsilyl ether as a highly efficient bifunctional organocatalyst for Michael addition of ketones and aldehydes to nitroolefins

✍ Scribed by Chao Wang; Chun Yu; Changlu Liu; Yungui Peng

• Book ID: 104096379
• Publisher: Elsevier Science
• Year: 2009
• Tongue: French
• Weight: 310 KB
• Volume: 50
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/j.tetlet.2009.02.211

✦ Synopsis

4-Trifluoromethanesulfonamidyl prolinol tert-butyldiphenylsilyl ether bifunctional organocatalyst 3a is a highly efficient catalyst for the asymmetric Michael addition reactions of ketones and aldehydes to nitrostyrenes, leading to syn-selective adducts with excellent yields (>99%), high diastereoselectivities (up to 99:1 dr) and excellent enantioselectivities (up to 99% ee). Control experiments suggested that the transconfiguration relationship between the bulky group (-CH 2 OTBDPS) and the sulfonamido group at the 4position of the pyrrolidine ring was important to achieve high yield and stereoselectivity.